Grinder



Dec. 23, 1930. C. POPPELMAN 1,786,262

GRINDER Filed May 27, 1927 2 Sheets-Sheet 2 l -n-- wu i Patented Dec. 23, 1930 PAT-ET @Erica j CAARPPELAN OF'gwiscQNsiiv i' l i GRINDER This invention relates to improvements in grinders and its purpose is to provide an improved machine'adapted for use ingrindving various hard materials. VThe i vention may be 'i used with particular advantage .in grindingthe residueV discharged from rendering apparatus in which fats and oils are rendered from animal products, this residue consisting of dried meat scraps, hair, bones and the like. Theprincipal objectY of the invention is to provide aimachine adapted to operate efficiently Vin breaking upend grinding varionshard materials fed thereto. A'further object'is to provide a grinding inachine having` rotating grinding elements coing elements locatedwithin the spiral.' Still another object is to provide a grinding machine having a removable head to permit the cleaning and replacement of the screen and other parts of the grinding apparatus. :Other objects relate to various features of construction and arrangement which will appear more fully` hereinafter. Y

VThe nature of the invention'will be lunderstood Afrom the following specification taken with the accompanying drawings irlwhich one embodiment is illustrated. In 4the drawings,

Figure. 1 shows a transverse vertical sec tion taken on'the line 1-1of Fig. 2, and

Fig. 2 shows a vertical section taken on the line 2---2y of Fig. v1. l

The invention comprises la casing H lhaving` an outer curved wallv 11, the opposite sides ofwhich are extended downwardlyras 1927. Yserali No. 194,597.

Shoji/n atllf to form the opposite ,walls ofV a discharge chute 12. The outer wall 11 isy provided at one end with'a vertical wall 13V which is secured thereto in a suitable man ner andwhich is provided? in the lower part thereof with'an inlet opening 14 through whichljthe materials to be ground areA fed into the grinding-chamber 15.v The lower part of the end wall 13 iscontinued downwardly'at the bottom of the, grinding chamberfto form the rear wall v16 of the chute 12 and the front portions ofthe inclined walls 11a` are unitedby the front wall17 of the chute, Thematerials to be ground are fed to the opening 14 through a feed-hopper 18 -wliich'is attached tothe end wall y13 and which terminates preferably above the casing 10. The outerwall of the hopper 18 `is inclined downwardly and inwardlyy and ther lower kportion thereof'- curved inwardly atftlie lower edge of the opening la as shown at 19 so that the materials rfed into the hop.- per are directed by gravity-into the grindingchamber. The front wall 2O of the grinding chamber is constructed in the form of a circular metalplate adapted to overlap .the flanges 21`of the casing lO-to which the wall 20'issecured bybolts 22 and'nuts 23,thus making it .possible to remove this frontwall readily from the .casingwhen desired.

The grinding member hascertain-mov-V able grinding elements located therein and actuated by a horizontal shaft 25 the', rear end of which is journaled in a bearing =26 secured to the 'wall ofthe hopper 18 and'itted with roller bearings 26a while. the forward end thereof is journaled in a bearing 27 secured' to the removable front wall and fitted with roller bearings 27. A pulley 28 isy vsecured on the .shaft adjacent the bearing 26 and is adapted to be connected by a belt with: a motor or other source of power. The shaft .25 has two circular disks BO secured thereon Vley/keys 31, the inner disk being seated against a collar 32 which is secured on the shaft 25 by means of a set screw 33. The two disks which are spaced apart to .occupy positions adjacent the end walls of the grinding chamber are connected by two rods or pins 35 which are located-in the same plane containing the axis ty.' A..

` ic shaft and which are located equal ences rom that airis. The rods 35 have en "f'ed heads 35 which engage the outer side of the inner disk and their forward ends are provided with removable transfer pins 3G. Washers 3T are located between the pins and the outer face of the outer disk 3 so that longitudinal play of the rods 35 is prevented. Each rod has a plurality of grinding bars or arms 38 pivotall T7 mounted thereon and spaced apart by means of collars or bushings 39. 'lhese grinding arms are mounted to turn freely on the rods 35 but are normally held outwardly by centrifuforce when the shaft and the arms are ed in the direction indicated by the arrow l0 in Fig. l.

rlie rotatable grinding arms 38 are adapted to cooperate with an annular screen 4l made up of a relatively heavy metal plate having a plurality of apertures 42 therein, these apertures being preferably circular in form and distributed throughout t ne area or the screen. 'l he screen 4l is constructed in the form of a spiral with the inner end thereof seated in a recess 44 in a stationary break bar 45 which extends between the walls 13 and 20, preferably in a position directly above the shaft rllhe bar preferably comprises a plurality of complementary bars or shims 45u which are located between the inner portion of the bar and the outer casing wall ll, these complementary parts of the bar being secured to the casing by studs 46 which pass through holes in the casing wall and threadedly enthe lower bar section. By this arrangement, one or more of the complementary bar sections may be removed and replaced by another of different thickness in order to vary the position of the lower bar section and particularly the position of the breaking edge 45 thereof; The screen 41 has the outer edges of its outer surfaces seated against the inwardly directed flanges of angle bars 47 which are secured to the end wall 13 and to the removable wall 2O by means of rivets 48 and other bars 49 are secured to the wall 13 to engage the inner surfaces of the edge of the screen. rJ'Che outer edge of the spiral screen is preferably seated in a recess 51 formed in the outer bar section 45n but the screen merely bears against the flanges of the angle bars 4T so that after the cover 20 has been removed, the screen 4l may be engaged and withdrawn by moving it outwardly parallel to the :iis of the shaft 25. To permit the removal of the cover 20 without displacing the shaft 25, the outer end of the shaft is provided with a collar 53 normally secured in place by a detachable transverse pin 54. When the screen 4l is in place in the casing l0, it forms the outer wall of the grinding chamber l5 and a space 55 is thus provided around the screen and around the grinding chamber in which the ground materials colmee-,262

lect after passing through the apertures of the screen 4l and thence pass downwardly by gravity through the discharge chute l2.

In the operation of this improved grinding machine, the materials to be ground fall by gravity' into the lower part of the grinding chamber l5 and are there engaged by the rotating grinding arms 38 which are free to move rearwardly upon impact with the materials and which tend to carry these materials upwardly against the force of gravity as they travel around the axis of the shaft 25. frs the materials are thus carried around they are projected outwardly by centrifugal force and the action of this force coupled with the grinding action of the outer ends of the members 38 serves to pulveriae the materials and force the finely divided particles thereof through the apertures 42 of the screen. The heavier particles and those which are not reduced by the cooperating action of the members 38 and the screen 4l are carried upwardly to the upper part of the grinding chamber and the action of centrifugal force causes these particles to be projected into the pocket 56 adjacent the vertical face of the break bar 45. As soon as these particles are lodged in these pockets they tend to ret-urn by gravity and are caught by the next series of rotating bars 38, being thereby broken against the breaking edge 45b of the bar. In this way bones and other hard objects in the materials to be ground are effectively broken against the bar 45 and this impact and breaking action takes place intermittently with the intervening rubbing action on the screen produced by the rotation of the members 38 so that, eventually, all of the materials are reduced to a friable condition and are forced outwardly through the apertures 42 of the screen. As the bar 45 wears ofi", it may be adjusted downwardly by varying the thickness of the shims 45 and this may be effected at other times in order to vary the space between the lower edge of the break bar and the outer ends of the grinding arms 38. Any of the parts which are likely to become worn with extended use, such as the arms 38, the bar 45 and the screen 4l may be readily replaced by removing the collar 53 and nuts 23 to permit the detachment of the cover 2O after which the outer disk 30 may be removed to permit access to the arms 38 while at the same time permitting the removal of the screen 4l and the replacement or adjustment of the bar 45.

An important advantage of this invention is that the materials to be ground are fed into the grinding chamber at the end thereof, preferably more or less into the suction area created by the rotation of the grinding elements so that the action of these rotating elements tends to draw the materials into the grinding chamber and there is no tendency of the rotating bars 38 to project thema-` terials out through the feeding hopper as in other forms of grinders employing rotating parts and having the feed hopper arranged to direct the materials throughthe outer peripheral wall of the grinding chamber. This arrangement of the feeding hopper whereby the materials are directed into the` end of the grinding chamber also brings about an improved screening efliciency due to' the relatively large'screenin@ area arising from the fact that it is postible to extend the screen throughout tlieperipl'iery of the Y tially closed chamber having a. central axial inlet and a peripheral discharge of the ground material, is also of advantagel due to the blower action set up by the rotating grinding elements which results in the ground materials being more effectively discharged outwardly through the screen and then blown outwardly through the Vdischarge chute l2 which may be directed at any suitable angle to deposit the ground materials at the desired place. Then in operation, the shaft 25 is preferably rotated at a relatively high speed, for example, a speed of 1800 to 3000 revolutions per'minute depending on the radius of the grinding chamber, so that the effect of the suction at the intake and of the blower action at the discharge outlet will be correspondingly increased. The simplicity of construction which permits all of the movable and stationary grinding elements to be removed readily from the casing, is of advantage not only in permitting lthe repair andl replacement of parts but in allowing the siibstitution of screens having perforations of diiferent size to suit the character of material being ground. Notwithstanding the fact that the screen has been referred to herein as of spiral7 form, it is preferably not a true spiral but formed on the arc of a circle through about three-quarters of its periphery so that the major portion thereof lies in relatively close proximity to the outer ends of the grinding members 38. v

Although one form of the invention has been shown and described by way of illustration, it will be understood that it may be constructed in various other forms wi th in the scope of the appended claims.

I claim:

l. The combination in a grinder of rotary grinding means and a spiral wall vsurrounding,

said grinding means andprovided with perforations throughout its annular extent, the ends of said spiral wall being spaced apart radially of the grinder, a break bar mounted betweensaid spaced ends, and a casingform ing a receiving chamber -around said perfo- Y `rated wall.V v

2. The combination in a grinder of a casing having :a grinding chamber therein, means for.deliveringmaterials to be ground to the lower part. of said chamber, rotary grindingmeans mounted in said chamber, and stationary grinding meansmounted'in the upper wall of saidchamberf and having an inwardly extending surface for cooperating with said rotary Vgrinding means.

3. The combination in a grinder of a casing havingva grinding chamber provided with a perforated wall, rotary grindingvmeans mounted in 'saidchamben a stationary break bar mountedin the upper part of said'chambei' to cooperate with said rotary grinding meanSVand'means for adjustingvertically Y the position of said bar.

t-. Thel combination in a grinder `of a rotary member, a plurality o Vmember, anda break bar interposed between the ends of -said-wall,\ saidV break bar being located above the axis of rotation of said member.

7. The combination in a grinder of a casing having end walls, one of said walls being removable, a spiral wall mounted between said end walls to form a grinding chamber, spiral supporting members Vattached to said `end walls Vfor holding said spiral wall in place, .and grinding means mounted within said spiral wall.

8. The combination in a grinder of a casing provided'with a grinding chamber, rotary grinding'means in said chamber, a stationary break bar in the upper part of said chamber, and means for feeding materials to be ground into said chamber transversely to the plane of rotation of said rotary grinding grinding arms f pivotedon said r-otaryinember, Aa spiral wallv extending around the `axis of-` said rotary iioV means and below the axis of rotation thereof.

the region within said screen in a direction substantially parallel tothe axis of rotation of said grinding means and below the aXis of rotation thereof.

l0. The combinati-on in a grinder of a rotary grindinof means, a surrounding Wall having the distance of its inner surface from the axis of said grinding means increasing progressively in the direction of rotation of said grinning means, and means located at the inner end of said surrounding Wall forming o a shoulder against which materials may be broken by the action oi" said rotary grinding means. Y

ll.' The combination in a grinder of rotary grinding means, a surrounding perfo- 15 rated Wall having the distance of its inner surface from the axis of said grinding means increasing progressively in the direction of rotation of said grinding means, a breaking member located between the displaced ends of .3 said perforated Wall and forming a shoulder against which materials may be broken by the action of said rotary grinding means, said spiral Wall forming a pocket of increasing depth to receive said materials adjacent said shoulder, and means for adjusting said breaking member radially of said rotary grinding means.

12. The combination in a grinder, of a casing having a grinding chamber therein, a ro- 3o tary grinder mounted in said grinding chamber, a perforated spiral Wall extending around said rotary grinder and increasing in radius in the direction of rotation thereof, and means separating the inner and outer ends of said spiral Wall and forming a break bar to cooperate With said grinding means.

in testimony whereof, I have subscribed my name.

CARL POPPELMAN. 

